One important element in maintaining plant growth, such as lawns, is the establishment of a consistent watering schedule. Too often, watering schedules are never established and the plants die because someone forgot to turn on the irrigation devices. For homeowners, vacations and business trips can make consistent watering schedules impossible. The resultant sporadic or catchup watering often proves ineffective, wasteful and may drown the plants or allow fungus, insects or other destructive elements to attack the plants.
In the urban environment, lawn watering is usually the most critical irrigational task faced by a homeowner. Electronically actuated sprinkler systems presently are used to compensate for human error factor in maintaining a well watered lawn. Unfortunately, these energy consuming systems are very difficult and expensive to install and hence are owned only by the most discerning homeowner. In an effort to place such systems within the economic reach of a larger number of homeowners, a battery-operated actuation system that waters lawns at timed intervals recently has been introduced. Although this system eliminates the need for running long lengths of electrical wiring, the batteries must be periodically changed and the total cost is still prohibitive to a large number of homeowners. Therefore, there has been a need for a device which can controllably and periodically switch lawn sprinklers and the like on-and-off, which requires no input power other than the pressurized water used for the irrigation itself, and which requires no expensive components or complex installation.